Exotic hadron in the context of "Gluons"

There are several proposed types of exotic matter:

• Hypothetical particles and states of matter that have not yet been encountered, but whose properties would be within the realm of mainstream physics if found to exist.
• Several particles whose existence has been experimentally confirmed that are conjectured to be exotic hadrons and within the Standard Model.
• States of matter that are not commonly encountered, such as Bose–Einstein condensates, fermionic condensates, nuclear matter, quantum spin liquid, string-net liquid, supercritical fluid, color-glass condensate, quark–gluon plasma, Rydberg matter, Rydberg polaron, photonic matter, Wigner crystal, Superfluid and time crystal but whose properties are entirely within the realm of mainstream physics.
• Forms of matter that are poorly understood, such as dark matter and mirror matter.
• Ordinary matter that when placed under high pressure, may result in dramatic changes in its physical or chemical properties.
• Degenerate matter
• Exotic atoms

In particle physics, the baryon number (B) is an additive quantum number of a system. It is defined as$${\displaystyle B={\frac {1}{3}}(n_{\text{q}}-n_{\rm {\overline {q}}}),}$$where ⁠${\displaystyle n_{\rm {q}}}$⁠ is the number of quarks, and ⁠${\displaystyle n_{\rm {\overline {q}}}}$⁠ is the number of antiquarks. Baryons (three quarks) have B = +1, mesons (one quark, one antiquark) have B = 0, and antibaryons (three antiquarks) have B = −1. Exotic hadrons like pentaquarks (four quarks, one antiquark) and tetraquarks (two quarks, two antiquarks) are also classified as baryons and mesons depending on their baryon number. In the Standard Model B conservation is an accidental symmetry which means that it appears in the Standard Model but is often violated when going beyond it. Physics beyond the Standard Model theories that contain baryon number violation are, for example, Standard Model with extra dimensions, Supersymmetry, Grand Unified Theory and String theory.

In particle physics, a tetraquark is an exotic meson composed of four valence quarks. A tetraquark state has long been suspected to be allowed by quantum chromodynamics, the modern theory of strong interactions. A tetraquark state is an example of an exotic hadron that lies outside the conventional quark model classification. A number of different types of tetraquark have been observed.

Z(4430) is a mesonic resonance discovered by the Belle experiment. It has a mass of 4430 MeV/c. The resonant nature of the peak has been confirmed by the LHCb experiment with a significance of at least 13.9 σ. The particle is charged and is thought to have a quark content of ccdu, making it a tetraquark candidate. It has the spin-parity quantum numbers J = 1.

The particle joins the X(3872), Zc(3900) and Y(4140) as exotic hadron candidates observed by multiple experiments, although it is the first to be confirmed as a resonance.

46°14′28″N 06°05′49″E / 46.24111°N 6.09694°E / 46.24111; 6.09694

The LHCb (Large Hadron Collider beauty) experiment is a particle physics detector collecting data at the Large Hadron Collider at CERN. LHCb specializes in the measurements of the parameters of CP violation in the interactions of b- and c-hadrons (heavy particles containing a bottom and charm quarks). Such studies can help to explain the matter-antimatter asymmetry of the Universe. The detector is also able to perform measurements of production cross sections, exotic hadron spectroscopy, and electroweak physics in the forward region. The LHCb collaborators, who built, operate and analyse data from the experiment, are composed of approximately 1650 people from 98 scientific institutes, representing 22 countries. Vincenzo Vagnoni succeeded on July 1, 2023 as spokesperson for the collaboration from Chris Parkes (spokesperson 2020–2023). The experiment is located at point 8 on the LHC tunnel close to Ferney-Voltaire, France just over the border from Geneva. The (small) MoEDAL experiment shares the same cavern.